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Finding the Fourth Proportional to 668.78, 921.83 and 528.65

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Solution

The fourth proportional to 668.78, 921.83 and 528.65 is: 728.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.78 : 921.83 = 528.65 : x
  2. Step 2: Convert to fraction form
    668.78/921.83 = 528.65/x
  3. Step 3: Cross multiply
    668.78x = 921.83 × 528.65
  4. Step 4: Simplify right side
    668.78x = 487,318.18
  5. Step 5: Solve for x
    x = 487,318.18/668.78
  6. Step 6: Final answer
    x = 728.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.